Improvement in casting metallic tubes



UNITED STATES nTnNT OFFICE..

JAMES SMITH, JR., OF NORTON, MASSACHUSETTS.

IMPROVEMENT IN CASTING METALLIC TUBES.

Specilication forming part oi' Letters Patent No. Mtlull, dated December t2, 1856.

To all Iii/1,0m it may concern:

Be it known that I, JAMES SMITH, Jr., o Norton, in the county of Bristol and State of Massachusetts, have invented an Improvement in Molds for Oastin g Metallic Tubes; and I do hereby declare that the same is fully described and represented in the following specication and the accompanying drawings, of which-n Figure l denotesa top view of one of my improved molds; Fig. 2, a side elevation of it; Fig. 3, a longitudinal section of it; Fig. 4, a transverse section; Fig. 5, an external view oi" its metallic core.

My invention is to be found in the manner in which I construct the said core. whereby it is notI only rendered capable of contraction in a transverse direction while in the mold and surrounded by hot metal in the act ot'cooling,

but of being easily taken apart, so as to separate it from a tube that may be cast upon it.

In the drawings, Aand B exhibit the two halves of the mold-shell, which are formed with not only a cylindrical matrix, c, for the reception of a core, C, but with a sprue-passage` I). The body ofthe core O ofthe mold, as shown in the drawings, is cylindrical in external form, and is composed of two stave sections or parts, c d, and a third or very narrow opening or stave, c, having a trapezoidal or wedge-shape form transversely. These stave/s are made at their opposite ends with shoulders o o and projections f j', so as to receive hoops or rings g g, which, after being made to encompass the staves, are with the staves held in place by two tapering plugs, 7i h. These plugs are driven into the heads of the core, respectively, and so as to spread the staves closely against their rings. The core thus constructed has a chamber or cylindrical space, i, within it. In the formation of those edges of the two major staves c d which rest against the opposite beveled edges of the minor or spring stave e they may be beveled or chamfered to conform to such edges of the stave e. The core, being thus made, is to be placed in the mold, as shown in the drawings, the two heads or ends m m of the mold being formed so as to closely embrace and t to the rings g g.

In casting metallic tubular ingots which are intended to be drawn out by rollers and converted into seamless metal tubes, it is desirable, for various reasons, to employ a metallic core' in the mold. The dirliculty attending the use of such a core has been that metal, when cast around it, would so shrink or contract on it as to render it extremely diftcult, if not impossible, subsequently to detach it from the core. The peculiar manner in which I construct the core, as hereinbefore specified, enables it to contract more or less transversely between its ends while metal cast around it and in the matrix may be in the process of contraction. Thus the cast metal has the opportunity of contracting without undue strain of its particles, the core giving away to the force of' contraction. After the metal has become set or suiiciently cool, the mold may be opened, and the core, with the tubular ingot, may be removed from the. matrix. This having been accomplished, I can easily separate the core from the casting, as in order to do so all that will be necessary will be to withdraw the plugs and rings from the ends ot' the staves and press the minor or contractile stave toward the axis ofthe core, so as to detach it from the others, which by the process will be loosened from the ingot, and with the other stave may be drawn out of the same.

I claim- The method of making the metallic moldcore-viz., of removable separate sections or staves c d and a narrow trapezoidal or wedgeshaped spring or stave, e-tlie whole being arranged and held together by rings g g and plugs, (or their mechanical equivalents,) and made to operate in manner substantially as above specified.

ln testimony whereof I havehereunto set my signature this 22d day of October, A. D. 1856. i

JAMES SMITH, J R.

'Witnessesz J osnri VILBAR, W. HENRY Gann. 

